Memory management method and storage controller

ABSTRACT

A memory management method for a storage device having a rewritable non-volatile memory module is provided. The rewritable non-volatile memory module has a plurality of physical blocks. The method includes: scanning the plurality of physical blocks to identify one or more bad physical blocks; performing a bad physical block remapping operation on the one or more bad physical blocks to update a virtual block stripe management table; and performing a writing operation under a multiple plane write mode based on the virtual block stripe management table.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 107114631, filed on Apr. 30, 2018. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a memory management method, and particularlyrelates to a management method and a storage controller for a storagedevice having a rewritable non-volatile memory module.

Description of Related Art

Generally speaking, if a rewritable non-volatile memory module has a badphysical block, the block stripe to which the bad physical block belongsmay not be available for data writing under a multiple plane write mode,or the block stripe to which the bad physical block belongs may be setas unusable.

Therefore, if the rewritable non-volatile memory module has a pluralityof dispersed bad physical blocks, the writing efficiency of therewritable non-volatile memory module may drop (as the multiple planewrite mode is unavailable for data writing), or the overall availablespace of the rewritable non-volatile memory module may be reduced (asthe block stripes to which the bad physical blocks belong may be set asunusable).

Therefore, finding out how to manage the bad physical blocks dispersedin the rewritable non-volatile memory module and reduce the adverseeffect of the bad physical blocks on the overall data accessingefficiency and/or the space for use of the rewritable non-volatilememory module is now an issue for people having ordinary skill in theart to work on.

SUMMARY OF THE INVENTION

The invention provides a memory management method and a storagecontroller for a storage device having a rewritable non-volatile memorymodule. The memory management method and the storage controller arecapable of performing remapping on an identified bad block to obtain agreater number of virtual block stripes available for a multiple planewrite mode and thereby improve a data accessing efficiency of thestorage device.

An embodiment of the invention includes a memory management method for astorage device having a rewritable non-volatile memory module. Therewritable non-volatile memory module has a plurality of physicalblocks, the physical blocks are divided into N planes, and each of the Nplanes has M physical blocks corresponding to M block stripes andordered based on a first order. M and N are positive integers. Themethod includes: scanning the physical blocks to identify one or morebad physical blocks from the physical blocks; performing a bad physicalblock remapping operation on the one or more bad physical blocks toupdate a virtual block stripe management table; and perform a writingoperation under a multiple plane write mode based on the virtual blockstripe management table. The bad physical block remapping operationincludes: determining whether there is one or more available physicalblocks ordered after a j^(th) physical block in an i^(th) plane of the Nplanes if the j^(th) physical block in the i^(th) plane is identified asa bad physical block, wherein i is a positive integer less than or equalto N, and j is a positive integer less than or equal to M, wherein if itis determined that there are the one or more available physical blocksordered after the j^(th) physical block in the i^(th) plane, a lastavailable physical block in the one or more available physical blocks ischosen based on the first order as a sacrificed physical block forfixing the j^(th) physical block, and mapping information correspondingto the j^(th) physical block recorded in the virtual block stripemanagement table is updated based on a physical address of thesacrificed physical block to complete the bad physical block remappingoperation corresponding to the j^(th) physical block, wherein themapping information corresponding to the j^(th) physical block indicatesthat a physical address of the j^(th) physical block is replaced by thephysical address of the sacrificed physical block.

An embodiment of the invention provides a storage controller. Thestorage controller controls a storage device including a rewritablenon-volatile memory module. The storage controller includes a connectioninterface circuit, a memory interface control circuit, a block stripemanagement circuit unit, and a processor. The connection interfacecircuit is coupled to a host system. The memory interface controlcircuit is coupled to the rewritable non-volatile memory module, therewritable non-volatile memory module has a plurality of physicalblocks, the physical blocks are divided into N planes, and each of the Nplanes has M physical blocks corresponding to M block stripes andordered based on a first order. In addition, M and N are positiveintegers. The block stripe management circuit unit scans the physicalblocks to identify one or more bad physical blocks from the physicalblocks. The block stripe management circuit unit further performs a badphysical block remapping operation on the one or more bad physicalblocks to update a virtual block stripe management table. The processorinstructs the memory interface control circuit to perform a writingoperation under a multiple plane write mode based on the virtual blockstripe management table. The bad physical block remapping operationincludes the following: The block stripe management circuit unitdetermines whether there is one or more available physical blocksordered after a j^(th) physical block in an i^(th) plane of the N planesif the j^(th) physical block in the i^(th) plane is identified as a badphysical block, wherein i is a positive integer less than or equal to N,and j is a positive integer less than or equal to M. If it is determinedthat there are the one or more available physical blocks ordered afterthe j^(th) physical block in the i^(th) plane, the block stripemanagement circuit unit chooses a last available physical block in theone or more available physical blocks based on the first order as asacrificed physical block for fixing the j^(th) physical block, andupdates mapping information corresponding to the j^(th) physical blockrecorded in the virtual block stripe management table based on aphysical address of the sacrificed physical block to complete the badphysical block remapping operation corresponding to the j^(th) physicalblock. In addition, the mapping information corresponding to the j^(th)physical block indicates that a physical address of the j^(th) physicalblock is replaced by the physical address of the sacrificed physicalblock.

Based on the above, the embodiments of the invention provide the memorymanagement method and the storage controller capable of scanning andidentifying a bad physical block, performing the bad physical blockremapping operation on the identified bad physical block to update thevirtual block stripe management table, and perform a writing operationunder the multiple plane write mode based on the virtual block stripemanagement table, so as to generate multiple virtual block stripesavailable for the multiple plane write mode. Accordingly, the dataaccessing efficiency and the space of the storage device are increased.

In order to make the aforementioned and other features and advantages ofthe invention more comprehensible, embodiments accompanying figures aredescribed in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 is a schematic block diagram of a host system and a storagedevice according to an embodiment of the invention.

FIG. 2 is a flowchart illustrating a memory management method accordingto an embodiment of the invention.

FIG. 3 is a schematic view illustrating a plurality of block stripes ofa rewritable non-volatile memory module according to an embodiment ofthe invention.

FIG. 4A is a schematic view illustrating a bad physical block accordingto an embodiment of the invention.

FIG. 4B is a schematic view illustrating a block stripe having a badphysical block according to an embodiment of the invention.

FIG. 5 is a schematic view illustrating a bad physical block re-mappingoperation according to an embodiment of the invention.

FIG. 6A is a schematic view illustrating a virtual block stripemanagement table (a first virtual block stripe bitmap and a firstvirtual block stripe remapping table) according to an embodiment of theinvention.

FIG. 6B is a schematic view illustrating a virtual block stripemanagement table (a second virtual block stripe bitmap and a secondvirtual block stripe remapping table) according to another embodiment ofthe invention.

FIG. 7 is a flowchart illustrating a data writing method according to anembodiment of the invention.

DESCRIPTION OF EMBODIMENTS

In the present embodiment, a storage device includes a rewritablenon-volatile memory module and a storage device controller (which isalso referred to as a storage controller or a storage control circuit).Moreover, the storage device is used together with a host system, andthe host system may write data into the storage device or read data fromthe storage device.

FIG. 1 is a schematic block diagram of a host system and a storagedevice according to an embodiment of the invention.

Referring to FIG. 1, the host system 10 includes a processor 110, a hostmemory 120 and a data transfer interface circuit 130. In the presentembodiment, the data transfer interface circuit 130 is coupled to (i.e.,electrically connected to) the processor 110 and the host memory 120. Inanother embodiment, the processor 110, the host memory 120 and the datatransfer interface circuit 130 are coupled to each other through asystem bus.

The storage device 20 includes a storage controller 210, a rewritablenon-volatile memory module 220 and a connection interface circuit 230.The storage controller 210 includes a processor 211, a data transfermanagement circuit 212 and a memory interface control circuit 213.

In the present embodiment, the host system 10 is coupled to the storagedevice 20 through the data transfer interface circuit 130 and theconnection interface circuit 230 of the storage device 20 to implement adata access operation. For example, the host system 10 may store data tothe storage device 20 or read data from the storage device 20 throughthe data transfer interface circuit 130.

In the present embodiment, the processor 110, the host memory 120 andthe data transfer interface circuit 130 may be disposed on a motherboardof the host system 10. The number of the data transfer interface circuit130 may be one or plural. Through the data transfer interface circuit130, the motherboard may be coupled to the storage device 20 through awired or wireless manner. The storage device 20 is, for example, a flashdrive, a memory card, a solid state disk (SSD) or a wireless memorystorage device. The wireless memory storage device is, for example, amemory storage device based on various wireless communication techniquessuch as a near field communication (NFC) memory storage device, a WiFimemory storage device, a Bluetooth memory storage device or a low powerconsumption Bluetooth memory storage device (for example, iBeacon), etc.Moreover, the motherboard may also be coupled to a global positioningsystem (GPS) module, a network interface card, a wireless transmissiondevice, or various I/O devices such as a keyboard, a screen, a mouse, aloudspeaker, etc. through the system bus.

In the present embodiment, the data transfer interface circuit 130 andthe connection interface circuit 230 are interface circuits compatibleto a peripheral component interconnect express (PCI express) standard.Moreover, the data transfer interface circuit 130 and the connectioninterface circuit 230 use a non-volatile memory express (NVMe)communication protocol in between to perform data transmission.

However, it should be noted that the invention is not limited thereto,and the data transfer interface circuit 130 and the connection interfacecircuit 230 may also be compliant with a parallel advanced technologyattachment (PATA) standard, an institute of electrical and electronicsengineers (IEEE) 1394 standard, a serial advanced technology attachment(SATA) standard, a universal serial bus (USB) standard, a SD interfacestandard, an ultra high speed-I (UHS-I) interface standard, an ultrahigh speed-II (UHS-II) interface standard, a memory stick (MS) interfacestandard, a multi-chip package interface standard, a multi media card(MMC) interface standard, an eMMC interface standard, a universal flashstorage (UFS) interface standard, an eMCP interface standard, a CFinterface standard, an integrated device electronics (IDE) standard orother suitable standards. Moreover, in another embodiment, theconnection interface circuit 230 and the storage controller 210 may bepackaged in one chip, or the connection interface circuit 230 isdisposed outside a chip containing the storage controller 210.

In the present embodiment, the host memory 120 is used for temporarilystoring a command or data executed by the processor 110. For example, inthe present exemplary embodiment, the host memory 120 may be a dynamicrandom access memory (DRAM), a static random access memory (SRAM), etc.However, it should be noted that the invention is not limited thereto,and the host memory 120 may also be other suitable memory.

The storage controller 210 is used for executing a plurality of logicalgates or control commands implemented in a hardware form or firmwareform, and performing data writing, reading, and erasing operations onthe rewritable non-volatile memory module 220 according to commands ofthe host system 10.

To be more specific, the processor 211 of the storage controller 210 ishardware having computation capability, and is used for controlling awhole operation of the storage controller 210. Specifically, theprocessor 211 has a plurality of control commands, and when the storagedevice 200 operates, the control commands are executed for the datawriting, reading and erasing operations.

It should be noted that in the present embodiment, the processor 110 andthe processor 211 are, for example, central processing units (CPU),micro-processors or other programmable microprocessors, digital signalprocessors (DSP), programmable controllers, application specificintegrated circuits (ASIC), programmable logic devices (PLD) or othersimilar circuit devices, which are not limited by the invention.

In an embodiment, the storage controller 210 further has a read-onlymemory (not shown) and a random access memory (not shown). Particularly,the read-only memory has a boot code, and when the storage controller210 is enabled, the processor 211 firstly executes the boot code to loadthe control commands stored in the rewritable non-volatile memory module220 to the random access memory of the storage controller 210.Afterwards, the processor 211 may execute the control commands toperform the data writing, reading and erasing operations. In anotherembodiment, the control commands of the processor 211 may also be storedin a specific area of the rewritable non-volatile memory module 220 (forexample, a physical storage unit in the rewritable non-volatile memorymodule 220 used for storing system data) in form of program code.

In the present embodiment, as described above, the storage controller210 further includes the data transfer management circuit 212 and thememory interface control circuit 213. It should be noted that theoperations executed by the components of the storage controller 210 mayalso be regarded as operations executed by the storage controller 210.

The data transfer management circuit 212 is coupled to the processor211, the memory interface control circuit 213 and the connectioninterface circuit 230. The data transfer management circuit 212 is usedfor receiving instructions of the processor 211 to perform datatransfer. For example, data is read from the host system 10 (forexample, the host memory 120) through the connection interface circuit230, and the read data is written into the rewritable non-volatilememory module 220 through the memory interface control circuit 213 (forexample, the writing operation is performed according to a writingcommand coming from the host system 10). For another example, data maybe read from one or more physical units of the rewritable non-volatilememory module 220 (the data may be read from one or more memory cells ofthe one or more physical units) through the memory interface controlcircuit 213, and the read data is written to the host system 10 (forexample, the host memory 120) through the connection interface circuit230 (for example, the reading operation is performed according to areading command coming from the host system 10). In another embodiment,the data transfer management circuit 212 may also be integrated into theprocessor 211.

The memory interface control circuit 213 receives an instruction of theprocessor 211, and performs the writing (also referred to asprogramming) operation, reading operation or erasing operation to therewritable non-volatile memory module 220 in collaboration with the datatransfer management circuit 212.

For example, the processor 211 may execute a writing command sequence toinstruct the memory interface control circuit 213 to write data to therewritable non-volatile memory module 220. The processor 211 may executea reading command sequence to instruct the memory interface controlcircuit 213 to read data from one or more physical units, correspondingto the reading command, of the rewritable non-volatile memory module220. The processor 211 may execute an erasing command sequence toinstruct the memory interface control circuit 213 to perform an erasingoperation to the rewritable non-volatile memory module 220. The writingcommand sequence, the reading command sequence and the erasing commandsequence may respectively include one or more program codes or commandcodes and instruct to perform the corresponding writing, reading anderasing operation to thee writable non-volatile memory module 220. In anembodiment, the memory interface control circuit 213 may executecorresponding operations (e.g., a bad block scanning operation, a lossbalancing operation, a garbage collecting operation, and/or the like)based on other command sequences that are received. These commandsequences may include one or more signals, or data on a bus. Thesesignals or data may include command codes or program codes. For example,the reading command sequence may include information such as a readidentification code, a memory address, etc., and the writing commandsequence may include information such as a logical address to bewritten, write data, and a write mode to be used (e.g., a single planewrite mode or a multiple plane write mode), etc.

Moreover, data to be written into the rewritable non-volatile memorymodule 220 is converted into a format that is acceptable to therewritable non-volatile memory module 220 by the memory interfacecontrol circuit 213.

The rewritable non-volatile memory module 220 is coupled to the storagecontroller 210 (the memory interface control circuit 213) and storesdata written by the host system 10. The rewritable non-volatile memorymodule 220 may be a single level cell (SLC) NAND flash memory module(i.e., a flash memory module where one memory cell may store 1 bit), amulti level cell (MLC) NAND flash memory module (i.e., a flash memorymodule where one memory cell may store 2 bits), a triple level cell(TLC) NAND flash memory module (i.e., a flash memory module where onememory cell may store 3 bits), a quadruple level cell (QLC) NAND flashmemory module (i.e., a flash memory module where one memory cell storesfour bits), a 3D NAND flash memory module or a vertical NAND flashmemory module, etc., or other memory modules having the samecharacteristics. The memory cells in the rewritable non-volatile memorymodule 220 are arranged in an array.

In the present embodiment, the rewritable non-volatile memory module 220has a plurality of word lines, and each of the word lines includes aplurality of memory cells. The memory cells on a same word line mayconstruct one or more physical programming units (physical pages). Inaddition, the physical programming units may form a physical unit (aphysical block or a physical erasing unit). The present embodiment takesthe TLC NAND flash memory module as an example. In other words, in thefollowing embodiment, a memory cell that may store three bit values mayserve as a physical programming unit (i.e., in each programmingoperation, a programming voltage is applied to one physical programmingunit after another to program data). In addition, each of the respectivememory cells may be divided into a lower physical page, a middlephysical page, and an upper physical page, each storing one bit value.

In the embodiment, the memory cell is the smallest unit for data writing(programming). The physical unit is the smallest unit for erasing. Inother words, each physical unit contains the minimum number of memorycells to be erased together. Each physical unit has a plurality ofmemory cells.

In the following embodiment, an example where one physical block servesas one physical unit is described. However, in another embodiment, onephysical unit may also be formed by an arbitrary number of memory cells,depending on the practical needs. Besides, it should be understood thatwhen the processor 211 groups the memory cells (or physical units) inthe rewritable non-volatile memory module 220 to perform a correspondingmanagement operation, the memory cells (or physical units/physicalblocks) are logically grouped, while the physical positions of thememory cells remain the same.

FIG. 3 is a schematic view illustrating a plurality of block stripes ofa rewritable non-volatile memory module according to an embodiment ofthe invention.

Referring to FIG. 3, more specifically, the rewritable non-volatilememory module 220 may have a plurality of packages. Each of the packagesmay have a plurality of physical blocks. The physical blocks may bedivided into N planes, and part or all of the planes may be logicallydivided into a logical unit number (LUN). For the ease of description,it is assumed that the rewritable non-volatile memory module 220 has apackage D1, and the package D1 has a plurality of physical blocks. Thephysical blocks are divided (grouped) into four planes P1 to P4 (i.e.,N=4), and the four planes are divided into a logical unit number LUN1.In addition, each of the planes has M physical units ordered based on afirst order. For example, the plane P1 has M physical blocks P1(1) toP1(M), the plane P2 has M physical blocks P2(1) to P2(M), the plane P2has M physical blocks P3(1) to P3(M), and the plane P4 has M physicalblocks P4(1) to P4(M). In the embodiment, the physical blocks ordered atthe same position in the respective planes form a block stripe. Forexample, a block stripe BS(1) includes a physical block P1(1), aphysical block P2(1), a physical block P3(1), and a physical blockP4(1). In other words, all the physical blocks in the above four planesmay form M block stripes BS(1) to BS(M) ordered in the first order.

In the embodiment, the storage controller 210 sequentially writes databased on the order of the block stripes. For example (first example),assuming that all the block stripes are blank, in order to write datathat fills four physical blocks, the storage controller 210 may startfrom the first blank block stripe (the block stripe BS(1) in the currentexample) based on the first order and store the write data to all thephysical blocks (e.g., the physical block P1(1), the physical blockP2(1), the physical block P3(1), and the physical block P4(1)) of thefirst blank block stripe. In another example (second example), assumingthat the physical block P1(1) of the block stripe BS(1) is unavailablefor storing data, while other physical blocks are available to store thewrite data, the storage controller 210 may store the write data to thephysical block P2(1), the physical block P3(1), and the physical blockP4(1) of the block stripe BS(1) and the physical block P1(2) of theblock stripe BS(2).

In the embodiment, if all the physical blocks respectively correspondingto all the planes in the block stripe to be written are available forstoring data (e.g., blank), the storage controller 210 may adopt themultiple plane write mode to store the write data to the block stripe(also referred to as “performing a multiple plane write operation on theblock strip”). The multiple plane write mode may also be referred to asa full plane write mode. For instance, in the first example above, thestorage controller 210 may adopt the multiple plane write mode to storethe write data.

Alternatively, if one or more physical blocks (e.g., damaged physicalblocks, bad physical blocks, or physical blocks already storing data) ofall the physical blocks respectively corresponding to all the planes inthe block stripe to be written are unavailable for storing data, thestorage controller 210 may adopt the single plane write mode to storethe write data to the block stripe (also referred to as “performing asingle plane write mode to the block strip”). For instance, in thesecond example above, the storage controller 210 may adopt the singleplane write mode to store the write data.

More specifically, assuming that the storage controller 210 adopts themultiple plane write mode to store the write data to the four physicalblocks P1(1), P2(1), P3(1), and P4(1) of the block stripe BS(1)respectively corresponding to the planes P1 to P4 (e.g., the firstexample above), the storage controller 210 may divide the data into fourwrite sub-data, and respectively store the four write sub-data intowrite registers first corresponding to the four planes P1 to P4. Then,the storage controller may send only one programming command to writethe four write sub-data into the four physical blocks P1(1), P2(1),P3(1), and P4(1) in one step.

Alternatively, assuming that the storage controller 210 adopts thesingle plane write mode to store the three physical blocks P2(1), P3(1),and P4(1) respectively corresponding to the planes P2 to P4 in the blockstripe BS(1) and the physical block P1(2) corresponding to the plane P1in the block stripe BS(2) (e.g., the second example), the storagecontroller 210 may divide the write data into four write sub-data, andrespectively store the four write sub-data into the write registerscorresponding to the planes P1 to P4. Then, the storage controller 210needs to sequentially send four programming commands to separately storethe four write sub-data to the physical block P2(1), P3(1), P4(1), andP1(2). The operations sequentially include the following: the storagecontroller 210 sends a programming command to write the write sub-datastored in the write register of the plane P2 to the physical blockP2(1); the storage controller 210 sends a programming command to writethe write sub-data stored in the write register of the plane P3 to thephysical block P3(1); the storage controller 210 sends a programmingcommand to write the write sub-data stored in the write register of theplane P4 to the physical block P4(1); and the storage controller 210sends a programming command to write the write sub-data stored in thewrite register of the plane P1 to the physical block P1(2).

In other words, even if the size of the write data is the same, the timeconsumed by the programming operations for storing the write data underthe single plane write mode is more than the time consumed by theprogramming operation for storing the write data under the multipleplane write mode. It should be noted that, ss described above, exceptfor physical blocks with data already written normally, damaged physicalblocks (also referred to as “bad physical blocks”) may force the storagecontroller 210 to adopt the single plane write mode to store the writedata. As a result, the time consumed for the writing operation isincreased. Namely, the efficiency of the writing operation is reduced.The memory management method of the embodiment may reduce the adverseeffect of the bad physical blocks.

The applicable conditions of the multiple plane write mode and thesingle plane write mode and other details and relations of the modeswith the block stripes are already well known by people having ordinaryskills in the art and not the focus of the invention. Therefore, suchcontents will not be reiterated in the following.

The storage controller 210 may assign a plurality of logical units tothe rewritable non-volatile memory module 220. The host system 10 mayaccess user data stored in the physical units through the assignedlogical units. Here, each logical unit may be formed by one or morelogical addresses. For example, the logical unit may be a logical block,a logical page, or a logical sector. Each logical unit may be mapped toone or more physical units. In addition, the logical unit may be one ormore physical addresses, one or more physical sectors, one or morephysical programming units, or one or more physical erasing units. Inthe embodiment, the logical unit is a logical block, and a logicalsub-unit is a logical page. Each logical unit has a plurality of logicalsub-units.

Besides, the storage controller 210 may build a logical to physicaladdress mapping table and a physical to logical address mapping table torecord the mapping relations between the logical units (e.g., logicalblocks, logical pages, or logical sectors) assigned to the rewritablenon-volatile memory module 220 and the physical units (e.g., physicalerasing units, physical programming units, or physical sectors). Inother words, the storage controller 210 may look for a physical unitmapped to a logical unit based on the logical to physical addressmapping table, and the storage controller 210 may look up a logical unitmapped to a physical unit based on the physical to logical addressmapping table. However, the technical concepts concerning mappingbetween the logical units and physical units are common technical meansfamiliar to people having ordinary skills in the art. Thus, details inthis regard will not be further described in the following.

In the embodiment, an error checking and correcting circuit 214 iscoupled to the processor 211 and used for performing an error checkingand correcting operation to ensure the accuracy of data. Specifically,when the processor 211 receives a writing command from the host system10, the error checking and correcting circuit 214 may generate acorresponding error correcting code (ECC) and/or error detecting code(EDC). In addition, the processor 211 may write the data and thecorresponding ECC and/or EDC to the rewritable non-volatile memorymodule 220. Afterwards, when reading data from the rewritablenon-volatile memory module 220, the processor 211 may also read the ECCor EDC corresponding to the data, and the error checking and correctingcircuit 214 may perform the error checking and correcting operation tothe read data based on the ECC and/or EDC. Moreover, after the errorchecking and correcting operation, if the read data is successfullydecoded, the error checking and correcting circuit 214 may return anerror bit value to the processor 211.

In an embodiment, the storage controller 210 may further include abuffer memory 216 and a power management circuit 217. The buffer memoryis coupled to the processor 211 and used for temporarily storing dataand commands from the host system 10, data from the rewritablenon-volatile memory module 220, or other system data used for managingthe storage device 20. Accordingly, the processor 211 may quickly accessthe data, the command, or the system data from the buffer memory 216.The power management circuit 217 is coupled to the processor 211 andused for controlling power of the storage device 20.

In the embodiment, a block stripe management circuit unit 215 includes abad block scanning circuit 2151 and a mapping table management circuit2152. The block stripe management circuit unit 215 sets up/updates aplurality of virtual block stripes and a corresponding virtual blockstripe management table (e.g., a bad physical block remapping operationto be described in the following) based on the identified bad physicalblock. In this way, the identified bad physical block may be fixedthrough the bad physical block remapping operation performed on the badphysical block, and the adverse effect of the bad physical block maythus be reduced.

In the embodiment, the processor 211 may instruct the bad block scanningcircuit 2151 in the block stripe management circuit unit 215 to performthe bad physical block scanning operation at one of the followingtimings: (1) when the storage device 20 is not occupied (i.e., when thestorage device 20 is idling over a predetermined time threshold); (2) atthe time when the storage device is turned on; and (3) when the numberof error bits of data read from a physical block exceeds an error bitnumber threshold. The operation may scan all or some specific (e.g., thephysical block meeting (3) above) physical blocks to determine whetherthe scanned physical block is a bad physical block. In addition, the badblock scanning circuit 2151 may identify the physical address (oridentification code) of the physical block determined as a bad physicalblock. In another embodiment, the processor 211 may choose a physicalblock in a worse physical state (e.g., a physical block having a greaternumber of program erase cycles or a greater error bit number) as thephysical block to be scanned based on one or a combination of thestatistics values and the error bit numbers of all the physical blocks.In an embodiment, the processor 211 may also randomly choose a targetphysical block to perform the bad physical block scanning operation.Details of the bad physical block scanning operation are technical meansthat people having ordinary skills in the art are familiar with, andthus will not be reiterated in the following.

In the following, details concerning the memory management method, howthe block stripe management circuit unit 215 carries out the badphysical block remapping operation, and the function of the mappingtable management circuit 2152 are described with reference to thedrawings.

FIG. 2 is a flowchart illustrating a decoding method according to anembodiment of the invention. It should be noted that the memorymanagement method shown in FIG. 2 may also be referred to as a badphysical block remapping method. Referring to FIGS. 1 and 2, at StepS21, the block stripe management circuit unit 215 scans a plurality ofphysical blocks to identify one or more bad physical blocks from thephysical blocks. The physical blocks are divided into N planes.Specifically, the processor 211 may instruct the bad block scanningcircuit 2151 in the block stripe management circuit unit 215 to performthe bad physical block scanning operation at the above-mentioned timingto identify the bad physical block present in the physical blocks of therewritable non-volatile memory module 220.

FIG. 4A is a schematic view illustrating a bad physical block accordingto an embodiment of the invention. FIG. 4B is a schematic viewillustrating a block stripe having a bad physical block according to anembodiment of the invention.

For the ease of description, it is assumed that M is 6. In other words,each plane has six physical blocks ordered based on the first order, andthere are six block stripes BS(1) to BS(6) in total. In addition, it isassumed that the bad block scanning circuit 2151 identifies bad physicalblocks P1(1), P1(3), P2(3), P3(3), P3(4), P4(3), P4(5) (e.g., the greyblocks) by performing the bad physical block scanning operation.Referring to FIG. 4B, the block stripes BS(1), BS(3), BS(4), and BS(5)are unavailable for writing data under the “multiple plane write mode”due to the presence of bad physical blocks. The block stripes BS(1),BS(3), BS(4), and BS(5) may be used to write data under the “singleplane write mode”. Comparatively, the block stripes BS(2) and BS(6)whose physical blocks are all normal and are available for writing dataunder the “multiple plane write mode”. According to the above example,it is known that even though the number of the bad physical blocksidentified are fewer than the number of the normal physical blocks, thepresence of the bad physical blocks significantly reduces the number ofthe block stripes available for writing data under the “multiple planewrite mode”. As a consequence, the number (e.g., 4) of the block stripesunavailable for the “multiple plane write mode” is even more than thenumber (e.g., 2) of the block stripes available for the “multiple planewrite mode”. Hence, the overall data accessing operation becomes lessefficient.

Accordingly, the processor 211 may instruct the block stripe managementcircuit unit 215 to perform the bad physical block remapping operationon the identified bad physical block. In other words, at Step S23, theblock stripe management circuit unit 215 may perform the bad physicalblock remapping operation on the one or more bad physical blocks toupdate the virtual block stripe management table. Specifically, for eachof the identified bad physical blocks, the block stripe managementcircuit unit 215 may determine whether to perform remapping on the badphysical block to virtually fix the bad physical block and thereby allowa virtual block stripe having the bad physical block to be available forwriting data under the multiple plane write mode.

Specifically, Step S23 include Steps S231, S233, and S235. At Step S231,if a j^(th) physical block in an i^(th) plane of the N planes isidentified as a bad physical block, the block stripe management circuit215 (e.g., the mapping table management circuit) may determine whetherthere is one or more available physical blocks ordered after the j^(th)physical block. i is smaller than or equal to N, and j is smaller thanor equal to M. Moreover, in the embodiment, an available physical blockis a block that can be configured to be written into, and can be anempty physical block, a physical block full of invalid data, or aphysical block containing valid data. If the physical block containsvalid data, it needs to perform Garbage Collection operation to move thevalid data first to other data block (or an open blcok), and thenperform the bad block remapping. In the embodiment, if the physicalblock is full of invalid data, the physical block would be performed theerase operation before being programmed data. In some embodiment, if thephysical block is full of invalid data, the physical block may beperformed the erase operation first, and then perform the bad blockremapping.

If it is determined that there is one or more available physical blocksordered after the j^(th) physical block in the i^(th) plane, theoperation proceeds to Step S233, and the block stripe management circuitunit 215 (e.g., the mapping table management circuit 2152) may choosethe last available physical block in the one or more available physicalblocks based on the first order as a sacrificed physical block forfixing the j^(th) physical block, and update mapping informationcorresponding to the j^(th) physical block recorded in the virtual blockstripe management table based on the physical address of the sacrificedphysical block to accomplish the bad physical block remapping operationcorresponding to the j^(th) physical block. In addition, the mappinginformation corresponding to the j^(th) physical block indicates thatthe physical address of the j^(th) physical block is replaced by thephysical addresses of the sacrificed physical block.

Alternatively, if it is determined that there is no one or moreavailable physical blocks ordered after the j^(th) physical block in thei^(th) plane, the operation proceeds to Step S235, and the block stripemanagement circuit unit 215 (e.g., the mapping table management circuit2152) does not fix the j^(th) physical block, but records the mappinginformation corresponding to the j^(th) physical block in the virtualblock stripe management table and ends the bad physical block remappingoperation corresponding to the j^(th) physical block. The mappinginformation corresponding to the j^(th) physical block indicates thatthe j^(th) physical block is a bad physical block that is not fixed. Inthe following, the bad physical block remapping operation is describedin detail with reference to FIG. 5.

FIG. 5 is a schematic view illustrating a bad physical block re-mappingoperation according to an embodiment of the invention. Referring to FIG.5, in an example, it is assumed that all the physical blocks are blank.In addition, it is assumed that the management circuit unit 215 performsthe bad physical block remapping operation on the physical block P1(1)(i.e., j=1), which is already identified as a bad physical block. Firstof all, as described in Step S231, the block stripe management circuitunit 215 (e.g., the mapping table management circuit 2152) may determinewhether there is any available physical block (i.e., a blank andavailable physical block) ordered after the physical block P1(1) in theplane P1. In the example, the block stripe management circuit unit 215may determine that the available physical blocks located in the plane P1and ordered after the physical block P1(1) based on the first order arethe physical blocks P1(2), P1(4), P1(5) and P1(6) (Even though thephysical block P1(3) is also blank, the physical block P1(3) is a badphysical block. Therefore, the physical block P1(3) is not an availablephysical block.

Then, the block stripe management circuit unit 215 may carry out StepS233. In other words, the block stripe management circuit unit 215 maychoose the last physical block from the available physical blocks P1(2),P1(4), P1(5), and P1(6) based on the first order as the physical block(also referred to as the sacrificed physical block) for fixing thephysical block P1(1). Then, the block stripe management circuit unit 215(e.g., the mapping table management circuit 2152) may replace thephysical address of the physical block P1(1) in the virtual block stripewith the physical address of the chosen sacrificed physical block (e.g.,P(1)→P(6) as shown in FIG. 5). After the physical address of the badphysical block P1(1) is replaced by the physical address of thesacrificed physical block P1(6) in the virtual block stripe, theoperation may also be construed as that the bad physical block P1(1) isfixed to be a fixed physical block. The block stripe management circuitunit 215 (e.g., the mapping table management circuit 2152) may recordthe mapping information of the fixed physical block P1(1) in the virtualblock stripe management table, and complete the bad physical blockremapping operation corresponding to the bad physical block P1(1).

It should be noted that the “fixed” described above is only in a virtualor logical sense, and fixing is carried out by remapping the physicaladdress of the bad physical block to the physical address of a normaland available physical block (the mapping table management circuit 2152may record the information with the virtual block stripe managementtable). In other words, any data accessing operation on the physicalblock P1(1) may be converted into a data access operation on thephysical block P1(6). The physical block P1(1) is still damagedphysically. It should be noted that, since the physical block P1(6) hasbecome a sacrificed physical block, the physical block P1(6) is nolonger determined as “available” (the mapping table management circuit2152 may record the information in the virtual block stripe managementtable). A sacrificed physical block may not be determined as anavailable physical block. A sacrificed physical block in the virtualblock stripe management table may be considered as unavailable. In otherwords, after the sacrificed physical block P1(6) is adopted to fix thebad physical block P1(1), the available physical blocks in the plane P1are reduced to the physical blocks P1(2), P1(4), and P1(5).

Similarly, regarding the bad physical block remapping operationperformed on the bad physical block P1(3), the block stripe managementcircuit unit 215 (e.g., the mapping table management circuit 2152) maychoose the available physical block P1(5) as a sacrificed physical blockfor fixing the bad physical block P1(3) (e.g., P1(3)→P1(5) as shown inFIG. 5).

Based on the same principle, the physical addresses of the bad physicalblocks P2(3), P3(3), P3(4), and P4(3) are all respectively remapped tothe physical addresses of the corresponding available physical blocksP2(6), P3(6), P3(5) and P4(6).

It should be noted that, in the bad physical block remapping operationperformed on the bad physical block P4(5), since the physical blockP4(6) ordered after the bad physical block P4(5) is a sacrificedphysical block (instead of an available physical block), the blockstripe management circuit unit 215 (e.g., the mapping table managementcircuit 2152) may determine that there is no available physical blockordered after the bad physical block P4(5) in the plane P4 and carry outStep S235. In other words, the block stripe management circuit unit 215(e.g., the mapping table management circuit 2152) does not fix the badphysical block P4(5), but records the mapping information correspondingto the bad physical block P4(5) in the virtual block stripe managementtable and ends the bad physical block remapping operation correspondingto the bad physical block P4(5). In other words, the physical blockP4(5) in a virtual block stripe VBS(5) may be labeled as unavailable(labeled as damaged).

After the bad physical block remapping operations on all the identifiedbad physical blocks are completed, the updating/setting up of thevirtual block stripe management table is also completed. After the badphysical block remapping operations on all the identified bad physicalblocks are completed, virtual block stripes VBS(1) to VBS(6) and theoriginal block stripes BS(1) to BS(6) show difference in that thevirtual block stripes VBS(1) to VBS(4) in the virtual block stripesVBS(1) to VBS(6) do not contain any unavailable physical blocks. The badphysical blocks originally present in the virtual block stripes VBS(1)to VBS(4) are fixed and become fixed physical blocks. More specifically,the block stripe BS(1) originally unavailable for writing data under the“multiple plane write mode” is converted into the virtual block stripeVBS(1), and the virtual block stripe VBS(1) is available for writingdata under the “multiple plane write mode”. The block stripe BS(3)originally unavailable for writing data under the “multiple plane writemode” is converted into the virtual block stripe VBS(3), and the virtualblock stripe VBS(3) is available for writing data under the “multipleplane write mode”. The block stripe BS(4) originally unavailable forwriting data under the “multiple plane write mode” is converted into thevirtual block stripe VBS(4), and the virtual block stripe VBS(4) isavailable for writing data under the “multiple plane write mode”. Inaddition, in the virtual block stripes VBS(1) to VBS(6), only thevirtual block stripes VBS(5) to VBS(6) are unavailable for writing dataunder the “multiple plane write mode”. In other words, by completing allthe bad physical block remapping operation, the number of block stripesunavailable for the “multiple plane write mode” is reduced from four totwo, and the virtual block stripes available for the “multiple planewrite mode” are closely arranged and ranked higher. Therefore, theoverall data accessing efficiency of the virtual data stripes VBS(1) toVBS(6) is facilitated (because the more the block stripes available forthe multiple plane write mode, the higher the overall data accessingspeed).

In the embodiment, the virtual block stripe management table may beclassified into a first type and a second type.

Specifically, if the virtual block stripe management table belongs tothe first type, the virtual block stripe management table includes afirst virtual block stripe bitmap and a first virtual block striperemapping table. A state column of the first virtual block stripe bitmaprecords M state values ordered based on the first order and respectivelycorresponding to the M virtual block stripes. Each of the state valuesincludes: a first type state value, indicating that all the physicalblocks in a virtual block stripe corresponding to the first type statevalue are normal, wherein the first type state value further indicatesthat the virtual block stripe corresponding to the first type statevalue does not contain any bad physical block; a second type statevalue, indicating that a virtual block stripe corresponding to thesecond type state value contains one or more bad physical blocks fixedthrough performing the bad physical block remapping operation; a thirdtype state value, indicating that a virtual block stripe correspondingto the third type state value contains one or more unavailable physicalblocks; or a fourth type state value, indicating that all the physicalblocks in a virtual block stripe corresponding to the fourth type statevalue are unavailable.

In addition, the first virtual block stripe remapping table includes Nplane columns corresponding to the N planes. In addition, each of the Nplane columns records the mapping information of the M physical blocksof the corresponding plane based on the first order. Each of the mappinginformation includes: a first type mapping value, indicating that aphysical block corresponding to the first type mapping value is not abad physical block, wherein the physical address of the physical blockcorresponding to the first type mapping value is the original physicaladdress; a second type mapping value, indicating that a physical blockcorresponding to the second type mapping value is a bad physical blockon which the bad physical block remapping operation is performed,wherein the second type mapping value further indicates the physicaladdress of the sacrificed physical block for fixing the physical blockcorresponding to the second type mapping value; a third type mappingvalue, indicating that a physical block corresponding to the third typestate value is a sacrificed physical block and is unavailable; or afourth type mapping value, indicating that a physical blockcorresponding to the fourth type state value is a bad physical block onwhich no bad physical block remapping operation is performed.

If the virtual block stripe management table belongs to the second type,the virtual block stripe management table includes a second virtualblock stripe bitmap and a second virtual block stripe remapping table.The second virtual block stripe bitmap includes a state column and anindex column. The state column records M state values ordered based onthe first order and respectively corresponding to the M virtual blockstripes. In addition, the index column records M index values orderedbased on the first order and respectively corresponding to the M virtualblock stripes. The types of the respective state values are similar tothe types of the state values of the virtual block stripe managementtable of the first type. Therefore, details in this regard will not berepeated in the following. In the M index values, an index valuecorresponding to the first type state value is a first type index value,and an index value corresponding to the second type state value, thethird type state value, or the fourth type state value is a second typeindex value. In addition, the second type index value includes apositive integer not greater than M. Besides, the second virtual blockstripe remapping table includes an index column and N plane columnscorresponding to the N planes. The index column records P index valuesbelonging to the second type index value among the M index valuesrecorded in the second virtual block stripe bitmap, wherein P is lessthan or equal to M. In addition, each of the N plane columns records themapping information of the P physical blocks of the P virtual blockstripes corresponding to the P index values. The respective mappinginformation is similar to the types of the mapping information of thevirtual block stripe management table of the first type. Therefore,details in this regard will not be repeated in the following. The Nplane columns of the second virtual block stripe remapping table recorda total of N×P mapping information.

In the following, FIG. 6A serves as an example to describe the virtualblock stripe management table of the first type, and FIG. 6B serves asan example of the virtual block stripe management table of the secondtype.

FIG. 6A is a schematic view illustrating a virtual block stripemanagement table (a first virtual block stripe bitmap and a firstvirtual block stripe remapping table) according to an embodiment of theinvention. Referring to FIG. 6A, following the example of FIG. 5, thevirtual block stripe management table of the first type includes a firstvirtual block stripe bitmap BMP1 and a first virtual block remappingtable RMPT1. The first virtual block stripe bitmap BMP1 has a statecolumn SF. The state column SF records six state values (M=6), i.e.,“1”, “0”, “1”, “1”, “2”, and “3” respectively corresponding to thevirtual block stripes VBS(1) to VBS(6) based on the first order.According to the above, the mapping table management circuit 2152 mayuse the first type state value (e.g., the bit value “0”) to indicatethat all the physical blocks in the corresponding virtual block stripeare normal (no bad physical block at all). For example, the state valuecorresponding to the virtual block stripe VBS(2) is recorded as “0”. Themapping table management circuit 2152 may use the second type statevalue (e.g., the bit value “1”) to indicate that the correspondingvirtual block stripe contains at least one fixed physical block. Forexample, the state values corresponding to the virtual block stripesVBS(1), VBS(3), and VBS(4) are recorded as “1”. The mapping tablemanagement circuit 2152 may use the third type state value (e.g., thebit value “2”) to indicate that the corresponding virtual block stripehas at least one unavailable physical block (e.g., a sacrificed physicalblock or a bad physical block). For example, the state valuecorresponding to the virtual block stripe VBS(5) is recorded as “2” (inother words, a virtual block corresponding to the third type state valueat least has one unavailable physical block, such as the physical blockP2(5)). The mapping table management circuit 2152 may use the fourthtype state value (e.g., the bit value “3”) to indicate that all thephysical blocks in the corresponding virtual block stripe areunavailable physical blocks. For example, the state value correspondingto the virtual block stripe VBS(6) may be recorded as “3” (because theall the physical blocks of the virtual block stripe VBS(6) areunavailable sacrificed physical blocks).

In the embodiment, the processor 211 may quickly determine whether eachof the virtual block stripes is available for writing data under themultiple plane write mode based on the first virtual block stripebitmap. Specifically, the virtual block stripes corresponding to thefirst type state value and the second type state value (e.g., thosecovered in a range 601) are determined as being available for writingdata under the multiple plane write mode. The virtual block stripescorresponding to the third type state value and the fourth type statevalue (e.g., those covered in a range 602) may be determined asunavailable for writing data under the multiple plane write mode. Itshould be noted that a virtual block stripe corresponding to the thirdtype state value may be adopted in a single plane write operation forwriting data to the available physical blocks in the virtual blockstripe corresponding to the third type state value.

Also, in an embodiment, a virtual block stripe corresponding to thefourth type state value may be skipped from any data accessing operation(because all the physical blocks in the virtual block stripecorresponding to the fourth type state value are unavailable).Accordingly, since the information of the fourth type state value isrecorded, the time consumed for some specific memory managementoperations may be saved (because the virtual block stripe correspondingto the fourth type state value may be ignored when some specific memorymanagement operations are executed).

It should be noted that the order of the state values recorded in thestate column SF of the first virtual block stripe bitmap BMP1 is basedon the order of the corresponding virtual block stripes. In other words,the virtual block stripe corresponding to a state value can be toldbased on the ordered position of the state value in the state column.For example, a state value ordered at the N^(th) position may correspondto a virtual block stripe VBS(N). In addition, the first virtual blockstripe bitmap BMP may also be integrated into the first virtual blockstripe remapping table RMPT1.

The first virtual block remapping table RMPT1 includes four planecolumns PF1 to PF4 (N=4) corresponding to the four planes. Each of theplane columns records the mapping information of the physical blocks ofthe corresponding virtual block stripe based on the first order. Forexample, the mapping information respectively recorded in the firstslots of the plane columns PF1 to PF4 are the mapping information of thephysical blocks belonging to the planes P1 to P4 in the virtual blockstripe VBS(1).

In the embodiment, the mapping table management circuit 2152 may set themapping information of physical blocks identified as normal(non-unavailable physical blocks, non-bad physical blocks) as the firsttype mapping value (e.g., “0”) (for example, after the bad physicalblock scanning operation is performed, the mapping table managementcircuit 2152 may set the mapping information of the non-bad physicalblocks as “0”).

In addition, after the bad physical block remapping operation isperformed, the mapping table management circuit 2152 may set the mappinginformation of sacrificed physical blocks in the bad physical blockremapping operation as the third type mapping value (e.g., “−1”), andset the mapping information of physical blocks fixed with the sacrificedphysical blocks, i.e., the corresponding fixed physical blocks, as thesecond type mapping value. In addition, the second type mapping valuerecords the ordered position of the sacrificed physical block in thesame plane (or the real physical address).

For example, referring to FIGS. 5 and 6A, the bad physical block P1(1)corresponding to the physical block stripe BS(1) in the plane P1 isfixed with the physical block P1(6) (i.e., the physical block orderedsixth in the plane P1). On such basis, the mapping information of thephysical block corresponding to the virtual block stripe VBS(1) in theplane column PF1 of the first virtual block stripe remapping table RMPT1is set as “6”, where “6” indicates that the physical block P1(1) isfixed with the physical block P1(6). In addition, the mappinginformation corresponding to the sacrificed physical block P1(6) in thefield column PF1 of the first virtual block stripe remapping table RMPT1is recorded as “−1”. In other words, with the mapping informationdescribed above, the processor 211 or the mapping table managementcircuit 2152 may learn: when a data accessing command instructs toperform data accessing on the physical block P1(1), data cannot beaccessed directly at the physical address of the physical block P1(1),but should be accessed at the physical address of the physical blockP1(6); and in searching for an available physical block in a datawriting operation, the physical block P1(6) may be considered asunavailable.

In the embodiment, the mapping table management circuit 2152 may set themapping information of a bad physical block (e.g., a bad physical blockon which the bad physical block remapping operation is not performed) asthe fourth type mapping value (e.g., “−2” or other predeterminednegative values). In other words, with the second type mapping value andthe fourth type mapping value, the processor 211 or the mapping tablemanagement circuit 2152 may identify the real physical addresses of allthe bad physical blocks (whether fixed or not) based on the values orpositions recorded in the second type mapping value and the fourth typemapping value.

FIG. 6B is a schematic view illustrating a virtual block stripemanagement table (a second virtual block stripe bitmap and a secondvirtual block stripe remapping table) according to another embodiment ofthe invention. FIG. 6B illustrates the virtual block stripe of thesecond type. The virtual block stripe of the second type differs fromthe virtual block stripe of the first type in the presence of the indexcolumn and that the second virtual block stripe remapping table of thesecond type has a smaller size than the size of the first virtual blockstripe remapping table of the first type. Referring to FIG. 6B,following the example of FIG. 5, the virtual block stripe managementtable of the second type includes a second virtual block stripe bitmapBMP2 and a second virtual block stripe remapping table RMPT2. The secondvirtual block stripe bitmap BMP2 includes the state column SF and anindex column IF. Similar to the example of FIG. 6A, the state column SFrecords six state values (M=6) respectively corresponding to the virtualblock stripes VBS(1) to VBS(6) based on the first order.

The index column IF records six index values (M=6) based on the firstorder. In addition, as described above, each index value type isdetermined based on the type of the state value. For example, the indexvalue of the virtual block stripe VBS(2) corresponds to the state valueas “0” (i.e., the first type state value). Therefore, the index value ofthe virtual block VBS(1) is determined as the first type index value (anindex value corresponding to the first type state value is determined asthe first type index value). In the embodiment, the value of the firsttype index value is a predetermined fixed bit value, such as “0” orother suitable bit values. In other words, as long as an index value isdetermined to be the first type index value, the value of the indexvalue is set as the predetermined fixed bit value, regardless of theordered position of the index value. In the embodiment, when theprocessor 211 or the block stripe management circuit unit 215 identifiesa virtual block stripe with the first type index value (or the firsttype state value), the processor 211 or the block stripe managementcircuit unit 215 may learn that all the physical blocks of the virtualblock stripe are normal physical blocks (i.e., physical blocks that arenot bad physical blocks, fixed physical blocks or sacrificed physicalblocks).

It should be noted that, in the embodiment, values of all the secondtype index values are assigned in an ascending manner based on the firstorder. For example, since the state values corresponding to the indexvalues of the virtual block stripes VBS(1), VBS(3), VBS(4), VBS(5), andVBS(6) belong to the second type state value, the third type statevalue, or the fourth type state value, the index values of the virtualblock stripes VBS(1), VBS(3), VBS(4), VBS(5), and VBS(6) are determinedas the second type index values. Then, based on the first order, thesecond index value ordered first is determined as “1”, and the secondindex value ordered P^(th) is determined as “P”. For example, in thecase of FIG. 6B, P is 5. In other words, the index value of the virtualblock stripe VBS(5) is the fifth index value among all the second typeindex values based on the first order and is set as “5”.

The second virtual block stripe remapping table RMPT2 includes the indexcolumn IF and the four plane columns PF1 to PF4 corresponding to thefour planes. The index column IF records all the second type indexvalues of the second virtual block stripe bitmap BMP2 based on the firstorder. In other words, the processor 211 or the block stripe managementcircuit unit 215 may identify an index value in the index column IF ofthe second virtual block stripe remapping table RMPT2 identical to aspecific second type index value in the index column IF of the secondvirtual block stripe bitmap BMP2, so as to look for the mappinginformation of the corresponding virtual block stripe in the secondvirtual block stripe remapping table RMPT2 based on the identical indexvalue. For example, it is assumed that the processor 211 or the blockstripe management circuit unit 215 intends to look for the mappinginformation of all the physical blocks of the virtual block stripeVBS(5). The processor 211 or the block stripe management circuit unit215 may identify the value of the index value of the virtual blockstripe VBS(5) as “4” in the second virtual block stripe bitmap BMP2, andthe processor 211 or the block stripe management circuit unit 215 mayturn to the index column IF of the second virtual block stripe remappingtable RMPT2 and identify the identical index value “4”, and identifyfour mapping information “−1 ”, “0”, “4”, and “−2” respectively recordedin the plane columns PF1 to PF4.

The types of all the mapping information of the second virtual blockstripe remapping table RMPT2 include the first type mapping value, thesecond type mapping value, the third type mapping value, and the fourthtype mapping value of the first virtual block stripe remapping tableRMPT1 described above. Therefore, details in this regard will not berepeated in the following.

It should be noted that the mapping information of the physical blocksof the virtual block stripe corresponding to the first type index valueis not recorded in the second virtual block stripe remapping tableRMPT2. Since all the physical blocks of the virtual block stripecorresponding to the first type index value are normal physical blocks,all the physical addresses of the physical blocks are the originallyassigned physical addresses (no remapping). To save space, the mappinginformation of these physical blocks are not recorded. In other words,the processor 211 or the block stripe management circuit unit 215adopting the virtual block stripe management table of the second typemay identify the ordered position (i.e., the physical address) of thephysical block of the virtual block stripe corresponding to the firsttype index value in a plane based on the ordered position of the virtualblock stripe corresponding to the first type index value.

In the embodiment, the processor 211 may quickly determine whether eachof the virtual block stripes is available for writing data under themultiple plane write mode based on the first virtual block stripebitmap. Specifically, the virtual block stripes corresponding to thefirst type state value and the second type state value are determined asbeing available for writing data under the multiple plane write mode(e.g., those covered in a range 601). The virtual block stripescorresponding to the third type state value and the fourth type statevalue may be determined as unavailable for writing data under themultiple plane write mode (e.g., those covered in a range 602). Itshould be noted that a virtual block stripe corresponding to the thirdtype state value may be adopted in a single plane write operation forwriting data to the available physical blocks in the virtual blockstripe corresponding to the third type state value.

It should be noted that, in the virtual block stripes obtained after thebad physical block remapping operations, the virtual block stripesavailable for applying the multiple plane write mode are closelyarranged at higher ranked positions. In other words, the virtual blockstripes unavailable for applying the multiple plane write mode areranked lower among all the virtual block stripes. In this way, forsequential data writing or writing of large-volume data, the badphysical blocks in the conventional process may result in fewer and lessevenly distributed virtual block stripes available for applying themultiple plane writing. However, in the embodiment, there are morevirtual block stripes available for applying multiple plane writing, andthese virtual block stripes available are closely arranged and rankedhigher. Thus, data writing becomes more efficient, and data integrityalso becomes more desirable.

It should be noted that the virtual block stripe management table ismaintained in the buffer memory 216 after the storage device 20 isturned on. Also, the virtual block stripe management table is backed upto the rewritable non-volatile memory module 220 at a specific timing.The virtual block stripe management table maintained in the buffermemory 216 may be updated in a timely manner due to a newly identifiedbad physical block after the corresponding bad physical block remappingoperation is completed.

In the embodiment, the updating of the virtual block stripe managementtable would not affect the updating of the logical to physical addressesmapping table. Specifically, when the processor 211 executes a writecommand which instructs to write data into first target logicaladdresses, the processor 211 checks the virtual block stripe managementtable to find a target virtual block stripe to store the data andidentifies first target physical addresses of first target physicalblocks in that target virtual block stripe which would be used to storethe data. After the data is written into the first target physicaladdresses, the processor 211 records the first target physical addressesinto the logical to physical addresses mapping table to map the firsttarget physical addresses to the first target logical addressesinstructed by the write command. It should be noted that the logical tophysical addresses mapping table still records the mapping relation ofthe logical addresses and the physical addresses only (does not recordthe “virtual” physical addresses). Moreover, when the processor 211executes a read command which instructs to read data from second targetlogical addresses, the processor 211 also read the logical to physicaladdresses mapping table to find the second target physical addressesmapped by the second target logical addresses, and then the process 211may read the data from the second target physical addresses directlywithout accessing the virtual block stripe management table.

For example, please refer FIG. 7, in the step S71, the processor 211receives a write command, wherein the write command instructs to writedata into a plurality of target logical addresses. The write command maybe sent from the host system 10. In the step S73, the processor 211queries a virtual block stripe management table to select a targetvirtual block stipe among a plurality of available virtual blockstripes, wherein the target virtual block stripe is used to store thedata. Specifically, the processor 211 may select one available virtualblock stripe (i.e., the target virtual block stripe) to write the datawith the multiple plane write mode, and the data would be written intothe selected virtual block stripe with the multiple plane write mode. Inthe step S75, the processor 211 identifies a plurality of targetphysical addresses of a plurality of target physical blocks of thetarget virtual block stripe. For example, if the selected virtual blockstripe is VBS(3), the processor 211 would identify the target physicalblocks P1(5), P2(6), P3(6) and P4(6) and the corresponding physicaladdresses of those physical blocks (e.g., P1(5), P2(6), P3(6) andP4(6)). In the step S77, the processor 211 programs the data into theplurality of the target physical addresses. Next, in the step S79, theprocessor 211 Updates a logical to physical addresses mapping tableaccording to the plurality of target physical addresses and theplurality of the target logical addresses, so as to record a mappingrelationship between the plurality of target physical addresses and theplurality of the target logical addresses and complete the writecommand. It should be noted that the processor does not need to recordthe information of the target virtual block into the logical to physicaladdresses mapping table. The data structures of the logical to physicaladdresses mapping table and the physical to logical addresses mappingtable may be as the same as the conventional art.

It should be noted that the processor 211 or the block stripe managementcircuit 215 may further record a valid count of each of the virtualblock stripes. For example, when the data stored in the physical blocksof a virtual block stripe gets updated with new write data, theprocessor 211 of the block stripe management circuit unit 215 may deductone from the valid count of the virtual block stripe to reflect the factthat the amount of valid data stored in the virtual block stripe isreduced. For example, assuming that the processor 211 intends to writedata to a logical block, and the logical block already stores old dataand is mapped to the physical block P1(6) (i.e., the sixth physicalblock of the plane P1), the processor 211 may write the data to anotheravailable physical block, treat the data of the physical block P1(6) asinvalid data (i.e., the data of the physical block P1(6) is updated),and look for the virtual block stripe VBS(1) corresponding to thephysical block P1(6) based on the virtual block stripe management table(since the plane column PF1 records the mapping information “6” that isordered first, and the mapping information corresponds to the virtualblock stripe VBS(1)). Accordingly, the processor 211 deducts one fromthe valid count of the virtual block stripe VBS(1).

When the valid count of a virtual block stripe is lower than athreshold, the processor 211 may perform a garbage collecting operationon the physical units of the virtual block stripe based on the mappinginformation in the virtual block stripe management table (e.g., thegarbage collecting operation performed on a physical block labeled withthe second type mapping value is actually performed at the physicaladdress of the corresponding sacrificed physical unit).

It should be noted that, the state values, the index values, and themapping values above are merely described for an illustrative purpose.With the inspiration above, people having ordinary skills in the art maymake suitable modification to record different types of state values,index values, and mapping values by adopting other values.

In an embodiment, the mapping information belonging to the third typemapping value may be recorded as a negative value corresponding to theordered position of the fixed physical block. For example, assuming thatthe bad physical block P1(2) is fixed with the physical block P1(5), thephysical block P1(5) is thus a sacrificed physical block, and themapping information thereof is recorded as “−2”, indicating that thephysical block corresponding to the sacrificed physical block P1(5) isthe second physical block in the plane P1 and corresponds to the virtualblock stripe VBS(2). It should be noted that, in the embodiment, themapping information belonging to the fourth type mapping value may berecorded as another specific value.

In view of the foregoing, the embodiments of the invention provide thememory management method and the storage controller capable of scanningand identifying a bad physical block, performing the bad physical blockremapping operation on the identified bad physical block to update thevirtual block stripe management table, and perform a writing operationunder the multiple plane write mode based on the virtual block stripemanagement table, so as to generate multiple virtual block stripesavailable for the multiple plane write mode. Accordingly, the dataaccessing efficiency and the space of the storage device are increased.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of theinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the invention covermodifications and variations of this invention provided they fall withinthe scope of the following claims and their equivalents.

What is claimed is:
 1. A memory management method for a storage devicehaving a rewritable non-volatile memory module, wherein the rewritablenon-volatile memory module has a plurality of physical blocks, thephysical blocks are divided into N planes, each of the N planes has Mphysical blocks corresponding to M block stripes and ordered based on afirst order, M and N being positive integers, and the memory managementmethod comprising: scanning the physical blocks to identify one or morebad physical blocks from the physical blocks; performing a bad physicalblock remapping operation on the one or more bad physical blocks toupdate a virtual block stripe management table; and performing a writingoperation under a multiple plane write mode based on the virtual blockstripe management table, wherein the bad physical block remappingoperation comprises: determining whether there is one or more availablephysical blocks ordered after a j^(th) physical block in an i^(th) planeof the N planes if the j^(th) physical block in the i^(th) plane isidentified as a bad physical block, wherein i is a positive integer lessthan or equal to N, and j is a positive integer less than or equal to M,wherein if it is determined that there are the one or more availablephysical blocks ordered after the j^(th) physical block in the i^(th)plane, a last available physical block in the one or more availablephysical blocks is chosen based on the first order as a sacrificedphysical block for fixing the j^(th) physical block, and mappinginformation corresponding to the j^(th) physical block recorded in thevirtual block stripe management table is updated based on a physicaladdress of the sacrificed physical block to complete the bad physicalblock remapping operation corresponding to the j^(th) physical block,wherein the mapping information corresponding to the i^(th) physicalblock indicates that a physical address of the j^(th) physical block isreplaced by the physical address of the sacrificed physical block. 2.The memory management method as claimed in claim 1, wherein if thevirtual block stripe management table belongs to a first type, thevirtual block stripe management table comprises a first virtual blockstripe bitmap and a first virtual block stripe remapping table, whereina state column of the first virtual block stripe bitmap records M statevalues ordered based on the first order and respectively correspondingto the M virtual block stripes, wherein each of the state valuescomprises: a first type state value, indicating that all physical blocksin a virtual block stripe corresponding to the first type state valueare normal, wherein the first type state value further indicates thatthe virtual block stripe corresponding to the first type state valuedoes not contain any bad physical block; a second type state value,indicating that a virtual block stripe corresponding to the second typestate value contains one or more bad physical blocks fixed throughperforming the bad physical block remapping operation; a third typestate value, indicating that a virtual block stripe corresponding to thethird type state value contains one or more physical blocks that areunavailable; or a fourth type state value, indicating that all physicalblocks of a virtual block stripe corresponding to the fourth type statevalue are unavailable, wherein the first virtual block stripe remappingtable comprises N plane columns corresponding to the N planes, whereineach of the N plane columns records mapping information of M physicalblocks of a corresponding plane based on the first order, wherein eachof the mapping information comprises: a first type mapping value,indicating that a physical block corresponding to the first type mappingvalue is not the bad physical block, and a physical address of thephysical block corresponding to the first type mapping value is anoriginal physical address; a second type mapping value, indicating thata physical block corresponding to the second type mapping value is a badphysical block on which the bad physical block remapping operation isperformed, wherein the second type mapping value further indicates aphysical address of a sacrificed physical block for fixing the physicalblock corresponding to the second type mapping value; a third typemapping value, indicating that a physical block corresponding to thethird type state value is a sacrificed physical block and isunavailable; or a fourth type mapping value, indicating that a physicalblock corresponding to the fourth type state value is a bad physicalblock on which the bad physical block remapping operation is notperformed.
 3. The memory management method as claimed in claim 1,wherein if the virtual block stripe management table belongs to a secondtype, the virtual block stripe management table comprises a secondvirtual block stripe bitmap and a second virtual block stripe remappingtable, wherein the second virtual block stripe bitmap comprises a statecolumn and an index column, the state column records M state valuesordered based on the first order and respectively corresponding to the Mvirtual block stripes, and the index column records M index valuesordered based on the first order and respectively corresponding to the Mvirtual block stripes, wherein each of the state values comprises: afirst type state value, indicating that all physical blocks in a virtualblock stripe corresponding to the first type state value are normal,wherein the first type state value further indicates that the virtualblock stripe corresponding to the first type state value does notcontain any bad physical block; a second type state value, indicatingthat a virtual block stripe corresponding to the second type state valuecontains one or more bad physical blocks fixed through performing thebad physical block remapping operation; a third type state value,indicating that a virtual block stripe corresponding to the third typestate value contains one or more physical blocks that are unavailable;or a fourth type state value, indicating that all physical blocks of avirtual block stripe corresponding to the fourth type state value areunavailable, wherein in the M index values, an index value correspondingto the first type state value is a first type index value, and an indexvalue corresponding to the second type state value, the third type statevalue, or the fourth type state value is a second type index value,wherein the second type index value comprises a positive integer notgreater than M, wherein the second virtual block stripe remapping tablecomprises an index column and N plane columns corresponding to the Nplanes, the index column records P index values belonging to the secondtype index value among the M index values in the second virtual blockstripe bitmap, P being less than or equal to M, wherein each planecolumn of the N plane columns records mapping information of P physicalblocks of P virtual block stripes corresponding to the P index values.wherein each of the mapping information comprises: a first type mappingvalue, indicating that a physical block corresponding to the first typemapping value is not the bad physical block, and a physical address ofthe physical block corresponding to the first type mapping value is anoriginal physical address; a second type mapping value, indicating thata physical block corresponding to the second type mapping value is a badphysical block on which the bad physical block remapping operation isperformed, wherein the second type mapping value further indicates aphysical address of a sacrificed physical block for fixing the physicalblock corresponding to the second type mapping value; a third typemapping value, indicating that a physical block corresponding to thethird type state value is a sacrificed physical block and isunavailable; and a fourth type mapping value, indicating that a physicalblock corresponding to the fourth type state value is a bad physicalblock on which the bad physical block remapping operation is notperformed, wherein the N plane columns of the second virtual blockstripe remapping table records a total of N×P mapping information. 4.The memory management method as claimed in claim 1, further comprising:not fixing the j^(th) physical block but recording the mappinginformation corresponding to the j^(th) physical block in the virtualblock stripe management table and ending the bad physical blockremapping operation corresponding to the j^(th) physical block if it isdetermined that there is no one or more physical blocks that areavailable and ordered after the j^(th) physical block in the i^(th)plane, wherein the mapping information corresponding to the j^(th)physical block indicates that the j^(th) physical block is a badphysical block that is not fixed.
 5. The memory management method asclaimed in claim 1, further comprising: not setting up a bad physicalblock table after the one or more bad physical blocks are identified,wherein physical addresses of the one or more bad physical blocks areidentified by the virtual block stripe management table.
 6. The memorymanagement method as claimed in claim 1, wherein performing the writingoperation under the multiple plane write mode based on the virtual blockstripe management table comprises: identifying write data correspondingto the writing operation; identifying one or more first virtual blockstripes based on the virtual block stripe management table, wherein theone or more first virtual block stripes do not contain any unavailablephysical block; and choosing a blank target virtual block stripe fromthe one or more first virtual block stripes, and simultaneously writingtarget write data in the write data to N target physical blocks of thetarget virtual block stripe respectively corresponding to the N planes,wherein the size of the target write data is less than or equal to atotal capacity of the N physical blocks.
 7. The memory management methodas claimed in claim 6, wherein simultaneously writing the target writedata in the write data to the N target physical blocks of the targetvirtual block stripe respectively corresponding to the N planescomprises: identifying N mapping information corresponding to the Nphysical blocks from the virtual block stripe management table based onthe target virtual block stripe; and identifying N physical addressesrespectively belonging to the N planes based on the N mappinginformation, so as to simultaneously write the target write data to theN physical addresses.
 8. The memory management method as claimed inclaim 1, wherein the writing further comprises: identifying an oldvirtual block stripe corresponding to old data based on the virtualblock stripe management table after the writing operation is performedif a logical address corresponding to the writing operation alreadystores the old data; and updating a valid data count of the old virtualblock stripe.
 9. A storage controller, controlling a storage devicecomprising a rewritable non-volatile memory module, the storagecontroller comprising: a connection interface circuit, coupled to a hostsystem; a memory interface control circuit, coupled to the rewritablenon-volatile memory module, wherein the rewritable non-volatile memorymodule has a plurality of physical blocks, the physical blocks aredivided into N planes, and each of the N planes has M physical blockscorresponding to M block stripes and ordered based on a first order, Mand N being positive integers; a block stripe management circuit unit;and a processor, coupled to the connection interface circuit, the memoryinterface control circuit, and the block stripe management circuit unit,wherein the block stripe management circuit unit scans the physicalblocks to identify one or more bad physical blocks from the physicalblocks, wherein the block stripe management circuit unit furtherperforms a bad physical block remapping operation on the one or more badphysical blocks to update a virtual block stripe management table,wherein the processor instructs the memory interface control circuit toperform a writing operation under a multiple plane write mode based onthe virtual block stripe management table, wherein the bad physicalblock remapping operation comprises: determining whether there is one ormore available physical blocks ordered after a j^(th) physical block inan i^(th) plane of the N planes by the block stripe management circuitunit if the j^(th) physical block in the i^(th) plane is identified as abad physical block, wherein i is a positive integer less than or equalto N, and j is a positive integer less than or equal to M, wherein if itis determined that there are the one or more available physical blocksordered after the j^(th) physical block in the i^(th) plane, the blockstripe management circuit unit chooses a last available physical blockin the one or more available physical blocks based on the first order asa sacrificed physical block for fixing the j^(th) physical block, andupdates mapping information corresponding to the j^(th) physical blockrecorded in the virtual block stripe management table based on aphysical address of the sacrificed physical block to complete the badphysical block remapping operation corresponding to the j^(th) physicalblock, wherein the mapping information corresponding to thej^(th)physical block indicates that a physical address of the j^(th)physical block is replaced by the physical address of the sacrificedphysical block.
 10. The storage controller as claimed in claim 9,wherein: wherein if the virtual block stripe management table belongs toa first type, the virtual block stripe management table comprises afirst virtual block stripe bitmap and a first virtual block striperemapping table, wherein a state column of the first virtual blockstripe bitmap records M state values ordered based on the first orderand respectively corresponding to the M virtual block stripes, whereineach of the state values comprises: a first type state value, indicatingthat all physical blocks in a virtual block stripe corresponding to thefirst type state value are normal, wherein the first type state valuefurther indicates that the virtual block stripe corresponding to thefirst type state value does not contain any bad physical block; a secondtype state value, indicating that a virtual block stripe correspondingto the second type state value contains one or more bad physical blocksfixed through performing the bad physical block remapping operation; athird type state value, indicating that a virtual block stripecorresponding to the third type state value contains one or morephysical blocks that are unavailable; or a fourth type state value,indicating that all physical blocks of a virtual block stripecorresponding to the fourth type state value are unavailable, whereinthe first virtual block stripe remapping table comprises N plane columnscorresponding to the N planes, wherein each of the N plane columnsrecords mapping information of M physical blocks of a correspondingplane based on the first order, wherein each of the mapping informationcomprises: a first type mapping value, indicating that a physical blockcorresponding to the first type mapping value is not the bad physicalblock, and a physical address of the physical block corresponding to thefirst type mapping value is an original physical address; a second typemapping value, indicating that a physical block corresponding to thesecond type mapping value is a bad physical block on which the badphysical block remapping operation is performed, wherein the second typemapping value further indicates a physical address of a sacrificedphysical block for fixing the physical block corresponding to the secondtype mapping value; a third type mapping value, indicating that aphysical block corresponding to the third type state value is asacrificed physical block and is unavailable; or a fourth type mappingvalue, indicating that a physical block corresponding to the fourth typestate value is a bad physical block on which the bad physical blockremapping operation is not performed.
 11. The storage controller asclaimed in claim 9, wherein: wherein if the virtual block stripemanagement table belongs to a second type, the virtual block stripemanagement table comprises a second virtual block stripe bitmap and asecond virtual block stripe remapping table, wherein the second virtualblock stripe bitmap comprises a state column and an index column, thestate column records M state values ordered based on the first order andrespectively corresponding to the M virtual block stripes, and the indexcolumn records M index values ordered based on the first order andrespectively corresponding to the M virtual block stripes, wherein eachof the state values comprises: a first type state value, indicating thatall physical blocks in a virtual block stripe corresponding to the firsttype state value are normal, wherein the first type state value furtherindicates that the virtual block stripe corresponding to the first typestate value does not contain any bad physical block; a second type statevalue, indicating that a virtual block stripe corresponding to thesecond type state value contains one or more bad physical blocks fixedthrough performing the bad physical block remapping operation; a thirdtype state value, indicating that a virtual block stripe correspondingto the third type state value contains one or more physical blocks thatare unavailable; or a fourth type state value, indicating that allphysical blocks of a virtual block stripe corresponding to the fourthtype state value are unavailable, wherein in the M index values, anindex value corresponding to the first type state value is a first typeindex value, and an index value corresponding to the second type statevalue, the third type state value, or the fourth type state value is asecond type index value, wherein the second type index value comprises apositive integer not greater than M, wherein the second virtual blockstripe remapping table comprises an index column and N plane columnscorresponding to the N planes, the index column records P index valuesbelonging to the second type index value among the M index values in thesecond virtual block stripe bitmap, P being less than or equal to M,wherein each plane column of the N plane columns records mappinginformation of P physical blocks of P virtual block stripescorresponding to the P index values. wherein each of the mappinginformation comprises: a first type mapping value, indicating that aphysical block corresponding to the first type mapping value is not thebad physical block, and a physical address of the physical blockcorresponding to the first type mapping value is an original physicaladdress; a second type mapping value, indicating that a physical blockcorresponding to the second type mapping value is a bad physical blockon which the bad physical block remapping operation is performed,wherein the second type mapping value further indicates a physicaladdress of a sacrificed physical block for fixing the physical blockcorresponding to the second type mapping value; a third type mappingvalue, indicating that a physical block corresponding to the third typestate value is a sacrificed physical block and is unavailable; and afourth type mapping value, indicating that a physical blockcorresponding to the fourth type state value is a bad physical block onwhich the bad physical block remapping operation is not performed,wherein the N plane columns of the second virtual block stripe remappingtable records a total of N×P mapping information.
 12. The storagecontroller as claimed in claim 9, wherein: the block stripe managementcircuit unit does not fix the j^(th) physical block but records themapping information corresponding to the j^(th) physical block in thevirtual block stripe management table and ends the bad physical blockremapping operation corresponding to the j^(th) physical block if it isdetermined that there is no one or more physical blocks that areavailable and ordered after the j^(th) physical block in the i^(th)plane, wherein the mapping information corresponding to the j^(th)physical block indicates that the j^(th) physical block is a badphysical block that is not fixed.
 13. The storage controller as claimedin claim 8, wherein: wherein after the one or more bad physical blocksare identified, the processor does not set up a bad physical blocktable, and the processor identifies physical addresses of the one ormore bad physical blocks based on the virtual block stripe managementtable.
 14. The storage controller as claimed in claim 9, wherein in theoperation that the processor instructs the memory interface controlcircuit to perform the writing operation under the multiple plane writemode based on the virtual block stripe management table, the processoridentifies write data corresponding to the writing operation, whereinthe processor identifies one or more first virtual block stripes basedon the virtual block stripe management table, and the one or more firstvirtual block stripes do not contain any unavailable physical block,wherein the processor chooses a blank target virtual block stripe fromthe one or more first virtual block stripes, and instructs the memoryinterface control circuit to simultaneously write target write data inthe write data to N target physical blocks of the target virtual blockstripe respectively corresponding to the N planes, wherein the size ofthe target write data is less than or equal to a total capacity of the Nphysical blocks.
 15. The storage controller as claimed in claim 14,wherein in the operation of instructing the memory interface controlcircuit to simultaneously write the target write data in the write datato the N target physical blocks of the target virtual block striperespectively corresponding to the N planes, the processor identifies Nmapping information corresponding to the N physical blocks from thevirtual block stripe management table based on the target virtual blockstripe, wherein the processor identifies N physical addressesrespectively belonging to the N planes based on the N mappinginformation, so as to instruct the memory interface control circuit tosimultaneously write the target write data to the N physical addresses.16. The storage controller as claimed in claim 9, wherein: the processoridentifies an old virtual block stripe corresponding to old data basedon the virtual block stripe management table after the writing operationis performed if an logical address corresponding to the writingoperation already stores the old data, wherein the processor updates avalid data count of the old virtual block stripe.